• Journal of Electrical Engineering and Technology
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• v.12 no.6
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• pp.2298-2306
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• 2017

A PMS (Power Management System) controls vessel's power systems to improve the system efficiency and to protect a blackout condition. The PMS should be developed with considering the type and the capacity of the vessel's power system. It is necessary to test the PMS functions developed for vessel's safe operations under various sailing situations. Therefore, the function tests in cooperation with practical power systems are required in the PMS development. In this paper, a hardware-in-the-loop (HIL) simulator is developed for the purposes of the PMS function tests. The HIL simulator can be more cost-effective, more time-saved, easier to reproduce, and safer beyond the normal operating range than conventional off-line simulators, especially at early stages in development processes or during fault tests. Vessel's power system model is developed by using a MATLAB/SIMULINK software and by communicating between an OPAL-RT's OP5600 simulator. The PMS uses a Modbus communication protocol implemented using LabVIEW software. Representative tests of the PMS functions are performed to verify the validity of the proposed HIL-based test platform.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.10
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• pp.1382-1387
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• 2018

There is a high demand for energy efficiency improvement of factories that make up a large part of national electric energy. Therefore, research on smart FEMS technology for monitoring, analyzing and controlling energy consumption patterns is under way, but there is still a lack of research on detailed element technology for communication and control inside the factory. In this paper, we proposed OFDM VLC system based on MODBUS protocol for communication between gateways, sensors, and devices to implement smart FEMS in indoor factory environment. Assuming a conveyor belt load control, we validated the proposed system by simulating the inverter motor control and checking the performance.

• Journal of Advanced Navigation Technology
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• v.12 no.5
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• pp.464-469
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• 2008

The RS-232C (Unbalanced serial) and RS-485 (balanced serial) are standard in serial communication. RS-485 uses a differential electrical signal, as opposed to unbalanced signals referenced to ground with the RS-232. Differential transmission, which uses two lines each for transmit and receive signal results in greater noise immunity and longer distances as compared to the RS-232C. The greater noise immunity and distance are big advantages in industrial environments. In general, one protocol on one serial interface is very normal application. In this study, we implemented multi protocols on one serial RS-485 interface and examine the performance and result with hanging multi equipments.

• Proceedings of the KIEE Conference
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• 2005.07d
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• pp.2652-2654
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• 2005

A vacuum chamber temperature control system of Pohang Accelerator Laboratory (PAL) storage ring is a subsystem upgraded PAL control system, which is based upon Experimental Physics and Industrial Control System (EPICS) [1]. There are two control components, data acquisition system (SA120 data logger), development control system IOC (Input/Output Controller) at the storage ring of PAL. There are 240 vacuum chamber at the storage ring. It was a very important problem to solve how to monitor such a large number of vacuum chamber temperature distributed around the ring. The IOC connect MODBUS/JBUS field network to asynchronous serial ports for communication with serial device. It can simultaneously control up to 4 data acquisition systems. Upon receiving a command from a IOC running under Windows2k through the network, the IOC communicate through the slave serial interface ports to SA120. We added some software components on the top of EPICS toolkit. The design of the vacuum control system is discussed. This paper describes the development vacuum chamber temperature control system and how the design of this system.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.10
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• pp.677-682
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• 2017

Lamination is used extensively in various industries. The type of lamination applied to the material depends on the precision level required, which varies for materials needed for everyday use, materials used in high-tech industries, and processes employed to fabricate finished products. Especially in hot lamination, the distribution of the surface temperature of the heating roller is very important to avoid the generation of internal bubbles and ensure flatness of the attached materials, and thus maintain a good standard of quality and productivity. In this study, we have developed a system to monitor the surface temperature of the heating rollerby applying a heterogeneous controller and a non - contact temperature sensor. This monitoring system accurately measures the surface temperature of the heating roller and applies the RS485 MODBUS communication method for easy expansion. Using this system, a laminated prototype was fabricated, and its efficacy for non-contact temperature sensor calibration, Ethernet IP communication, stoppage of the heating roller, and determination of temperature distribution with rotation was examined for its potential usage in industries.

• Proceedings of the KAIS Fall Conference
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• 2009.05a
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• pp.386-389
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• 2009

SCADA 시스템은 대개 생산 공정을 감시하고 제어하는데 사용되는 소프트웨어 패키지로써, 대부분 대규모 플랜트 상태를 감시하고 제어하기 위해 사용된다. 특히, 전력, 댐 철도, 원자력 등과 같은 주요 핵심기반시설에서 이를 활용한다. 기존 SCADA 시스템은 일반적으로 분리된 독자적 네트워크상에서 존재했기 때문에 보안에 소홀할 수밖에 없었다. 그러나 최근 기업정보시스템과의 연동 필요성으로 인해 아주 적게나마 원격에서 접속가능한 지점이 존재하고 이로 인한 취약성이 드러나고 있다. 이처럼 외부 공격에서의 취약성 분석을 통한 연구는 현재 진행 중에 있지만, 물리적인 접속을 통한 RTU Master와 Slave의 데이터를 직접적인 변조에 대한 연구는 이루어지지 않고 있다. Modbus RS485통신을 사용하는 SCADA 시스템의 특성상 RTU Master와 Slave는 RJ11 케이블을 통해 1km까지도 연결될 수 있는 상황이므로, 이러한 케이블에 물리적인 접속을 통하여 데이터를 Sniffing하고 Spoofing하는 것이 가능하다. 따라서 본 논문에서는 이러한 물리적인 접속을 통한 데이터 변조 공격에 대비하기 위하여 RSS를 활용한 보안 향상 방안에 대하여 연구하였고, 이러한 데이터 변조 공격을 검출해 낼 수 있는 모니터링 시스템에 대하여 제안하였다.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.2048-2049
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• 2007

광섬유 온도센서를 이용하여 밀폐형 폐쇄배전반 내부에 설치된 진공차단기(Vacuum Circuit Breaker: 이하 VCB)의 접촉부 및 부싱부 이상 온도변화를 상시 감시할 수 있는 On-line 온도 감시 시스템을 개발하였다. 본 시스템은 온도변화를 측정하는 광센서부, 광신호의 이동 통로역할을 하는 Optical Head부, 변환된 전기신호를 신호처리하고 상위 시스템으로 통신을 수행할 신호처리장치의 세 부분으로 구성되어 있다. 구현한 시스템은 측정 범위가 $-25\;{\sim}\;200^{\circ}C$인 희토류 원소가 첨가된 광섬유 온도센서를 사용하였고, 시스템의 측정 범위는 $-20\;{\sim}\;150^{\circ}C$, 측정 정밀도는 Full Scale의 ${\pm}2\;%$, 측정 주파수는 0.1 Hz이었다. 검출된 온도 값은 Modbus Protocol을 이용하여 상위 시스템으로 송신하도록 구현하였다.

• Journal of Korean Society of Water and Wastewater
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• v.31 no.3
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• pp.249-256
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• 2017

Recently, application areas based on M2M (Machine-to-Machine communications) and IoT (Internet of Things) technologies are expanding rapidly. Accordingly, water flow and water quality management improvements are being pursued by applying this technology to water and sewage facilities. Especially, water management will collect and store accurate data based on various ICT technologies, and then will expand its service range to remote meter-reading service using smart metering system. For this, the error in flow rate data transmitting should be minimized to obtain credibility on related additional service system such as real time water flow rate analysis and billing. In this study, we have identified the structural problems in transmitting process and protocol to minimize errors in flow rate data transmission and its handling process which is essential to water supply pipeline management. The result confirmed that data acquisition via communication system is better than via analogue current values and pulse, and for communication method case, applying the industrial standard protocol is better for minimizing errors during data acquisition versus applying user assigned method.

• Journal of Information Processing Systems
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• v.17 no.6
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• pp.1179-1190
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• 2021

A data acquisition and monitoring system was developed for an automated system of a smart fish farm. The fish farm is located in Jang Hang, South Korea, and was designed as circulation filtration system. Information of every aquaculture pool was automatically measured by pH sensors, dissolved oxygen sensors, and water temperature sensors and the data were stored in the database in a remoted server. Modbus protocol was used for gathering the data which were further used to optimize the pool water quality to predict the rate of growth and death of fish, and to deliver food automatically as planned by the fish farmer. By using JSON protocol, the collected data was delivered to the user's PC and mobile phone for analysis and easy monitoring. The developed monitoring system allowed the fish farmers to improve fish productivity and maximize profits.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.05a
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• pp.283-284
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• 2021

The domestic and overseas IoT (Internet of Things)-based automation industry is developing remarkably, and the development of this automation technology is further accelerated by the development of sensor technology. In recent years, the smart farm industry for the purpose of growing crops based on various sensor technologies is rapidly developing. In the case of smart farms, real-time monitoring and mobile services are provided by measuring representative environmental data such as temperature, humidity, and CO2 required for crop cultivation. Most of these environmental monitoring and control operations use the RS-485-based Modbus (RTU) communication method. In this paper, we intend to test the performance of sensor data and actuator information required for smart farm construction by building a platform for controlling sensor data and actuators based on LabView using MQTT (Message Queuing Telemetry Transport), an IoT standard protocol.